This invention generally relates to tuning circuits, and more specifically to a highly selective dual channel tuning network particularly useful for television and stereo applications.
Tuning circuits for amplifiers are well known. However, these are usually inactive or made of passive elements only. The present invention uses an active tuning circuit for each one of two information channels.
Also, because most prior art tuning circuits do not use feedback amplifiers in the tuning circuits, the tuning responses are generally broad bandwidth and less than totally satisfactory to tune an incoming signal or provide a good impedance match to circuitry that follows.
When tuning is desired of two signals in two separate channels, the prior art circuits do not provide for full flexibility, in a single and economical manner, for reversing the signals between channels and for selectively inhibiting the signals through one or both channels.